Radiation Detectors Explained: Why Every Household Needs One

Radiation was first discovered in the late 19th century, with Wilhelm Conrad Roentgen's discovery of x-rays in 1895 and Henri Becquerel's subsequent identification of natural radioactivity in uranium salts in 1896. With Marie Curie's discovery of radium and polonium, and her subsequent early death due to radium exposure, the world began to understand both the power and the danger that radioactivity can present.

Over a century later, detecting radiation remains critically relevant in today's world, especially amid concerns about nuclear proliferation and ongoing geopolitical conflicts. Tensions between nuclear-armed nations like U.S. and Russia only continue to rise, raising valid questions about the possibility of a third world war. In this volatile climate, the ability to detect and monitor nuclear radiation is essential not only for national security and environmental health, but for every American's personal safety and protection.

Source: Dan Meyers on Unsplash

Understanding Radiation and Detection

What Is Radiation?

Radiation refers to the spontaneous emission of particles or electromagnetic waves from the unstable nuclei of certain isotopes. This process transforms the original nuclei into different elements or isotopes, thus radiating energy.

The half-life of a radioactive substance is the time it takes for half of its atoms to decay. The longer a substance's half-life, the longer its radionuclides remain present in the environment after they are released.

There are three categories of radiation, each of which has distinct properties and relative levels of penetration power:

Alpha Radiation

Relatively heavy, positively charged helium nuclei (two protons and two neutrons).

Penetration power: Lowest

Can be stopped by: A sheet of paper or human skin

Hazard level: Not very dangerous externally, but are highly ionizing and can be very damaging if ingested or inhaled.

Where you might encounter it:

• Radon gas leaks in some homes, especially those with basements
  
  
• Sealed components of smoke detectors
  
  
• Naturally present uranium and radium in rocks and soil
  
  

Beta Radiation

High-speed electrons or positrons, lighter than alpha particles.

Penetration power: Low

Can be stopped by: Plastic or glass

Hazard level: Less dangerous than gamma particles, but still cause damage from both external and internal exposure.

Where you might encounter it:

• Nuclear fallout
  
  
• Scientific labs that perform experiments requiring high use of radiation, such as carbon dating
  
  
• Self-luminous electronic devices like exit signs and watches
  
  

Gamma Radiation

High-energy electromagnetic waves emitted from the nucleus of an atom.

Penetration power: High

Can be stopped by: Lead or thick concrete

Hazard level: Less ionizing than alpha particles, but can penetrate deeply into biological tissues

Where you might encounter it:

• Radiological cancer treatments
  
  
• Hospital equipment sterilization
  
  
• Medical diagnostic imaging
  
  

X-Rays

Similar to gamma rays, but emanate from electron interactions rather than nuclear processes.

Penetration power: Very high

Can be stopped by: Lead

Hazard level: Can penetrate deeply into biological tissue, and requires heavy protection to interact with safely

Where you might encounter it:

• Diagnostic imaging (radiography, dental scans)
  
  
• Airport baggage inspection
  
  
• Industrial material inspections
  
  

Source: Wikimedia Commons

Why Do We Need to Detect Radiation?

Radiation detection is about more than just preparing for a World War III apocalypse scenario. Radioactive materials have an undeniable and unavoidable presence in our modern world. Humans operate in environments with varying radiation levels daily, from the safely sealed components of smoke detectors and illuminated watches to the more hazardous materials involved in medical radiotherapy and highly specialized scientific testing.

Given the high potential for harm that dangerous radiation presents, it's important to prioritize radiation measurement and establish protocols or use radiation detection instruments to send alerts in case of radioactive contamination.

Radiation is measured in doses that help accurately assess relative levels of exposure. There are three ways to measure radiation: radioactivity, absorbed dose, and effective dose. All dosages can be measured using an international or SI (Systéme International) unit and a U.S. unit.

Radioactivity

Radioactivity is a measure of a material's rate of radioactive decay. It represents the total radiation emitted by a material and does not incorporate the radiation type, strength, or rate of absorbency.

The SI unit for radiation is the Becquerel (Bq), which is equivalent to one radioactive decay per second. Radiation can be measured in kilobecquerels or kBq (1,000 Bq), megabecquerels  or MBq (1,000,000 Bq), and gigabecquerels or GBq (1,000,000,000 Bq). 

The U.S. unit for radiation is the curie (Ci), which is the approximate number of radioactive decays in one gram of radium per second. Radiation can be measured in millicuries or mCi (.001 Ci), microcuries or µci (.000001 Ci), and picocuries or pCi (.000000000001 Ci).

Example: EPA guidelines state the maximum safe level of radium in drinking water is .185 becquerels per liter (Bq/L), or 5.0 picocuries per liter (pCi/L).

Absorbed Dose

When a being or object encounters a radioactive material, it will only absorb a portion of the material's radiation while the remainder of the radiation passes through the body. This method measures the dose equivalent that's absorbed by a person or object, and represents the amount of deposited radioactive energy in joules per unit of mass.

In radiology, the SI unit for absorbed dose is the gray (Gy), which is equivalent to one joule per kilogram of mass. Absorbed dose can be measured in centigrays or cGy (.01 Gy) and milligrays or mGy (.001 Gy).

The U.S. unit for absorbed dose is the Rad (rad), which is equivalent to .01 joule of energy per kilgram of mass. Absorbed dose can be measured in millirads or mrad (.001 rad) and kilorads or krad (1,000 rad). 

Example: The average absorbed dose of a single chest x-ray is about 10 mrad or .1 mGy, while the average absorbed dose of a CT scan of the abdomen and pelvis is about 1 rad or 1 cGy. 

Effective Dose

Absorbed dose only incorporates how much radiation remains in a body, but does not account for the type (and therefore strength) of the radiation and the sensitivity of the organ in question. Effective dose measures the amount of radiation absorbed in terms of its long-term health impacts. Unlike radioactivity and absorbed doses, effective dose is a calculated approximation made based on observed effects of past radiation exposure records.

The SI unit for effective dose is the Sievert (SV), which can be measured in milliSieverts or mSV (.001 Sv) and microSieverts or µSv (.00001 SV).

The U.S. unit for effective dose is the Rem (rem), which can be measured in millirems or mrem (.001 rem) and microrems or µrem (.000001 rem).

Example: The average effective dose of a single dental x-ray is 1.5 mrem or 15 µSv, while the average effective dose of a full body CT scan is 1 rem or 10 mSv.

Unveiling the World of Radiation Detectors

The Classic: Geiger Counters

Perhaps the most recognizable type of nuclear radiation detector is the Geiger counter. The Geiger counter radiation detector works by converting ionizing radiation into an electrical pulse proportional to the amount of radiation presence in a Geiger Muller tube. This pulse is then counted and displayed, typically in microSieverts per hour. 

Advantages

• Portability: These devices are small and easy to carry, making them ideal for field workers. A good radiation dosimeter with LCD display gives instant readings.
  
  
• Simplicity: Straightforward operation and immediate read-outs make these devices very user-friendly.
  
  
• Affordability: A quality device will only run a few hundred dollars, which makes them accessible for civilians. You can even buy these off Amazon.com.
  
  

Disadvantages

• Limited Measuring Capacity: These device aren't sensitive to detect the radiation at trace amounts, so they aren't precise enough for advanced scientific processes and experiments.
  
  
• Energy Identification: While these devices measure the amount of radiation present, they aren't able to differentiate between types of radiation particles.
  
  

Source: MIRA Safety

Beyond the Geiger: Exploring Other Detectors

Scintillation Detectors

Scintillators are substances that become luminescent when they're excited by ionizing radioactivity. Scintillation radiation devices use these materials to detect the radiation by converting the light emitted by the scintillating material and converting it into an electric signal that's proportional to the amount of radiation present.

Cloud Chambers

Cloud chambers are a type of analog detection device filled with a supersaturated vapor, or "cloud." When charged particles pass through the chamber, they ionize the gas along their path, causing the vapor to condense into tiny droplets and reveal the the trajectory of radioactivty. Users can interpret these tracks to determine the amount and type of radiation present.

Ionization Chambers

Ionization chambers detect radiation by measuring the electrical current created when ionizing radioactivity occurs in a gas-filled chamber. The resulting ions are collected by electrodes, generating a measurable electric current proportional to the amount of radiation. While the ionization chamber can report out the amount of radiation present in units, users must interpret the visible tracks within the generated magnetic field to determine the radiation type.

Personal Dosimeters

Personal dosimeters are worn as badges or wristbands and measure the accumulated dose of radiation over time. These radiation meters use materials like semiconductor detectors or film badges that record the total radiation dose absorbed. Film or thermoluminescent detectors last from a few weeks to a few months, while electronic radiation monitoring devices are designed to be used for a year or more and can be reset and reused after each reading. 

There are certain devices that are made for specialized purposes. For instance, you can get a Geiger counter nuclear radiation detector, which can be hooked up to an Android app to give you real-time information. Others, like a handheld beta gamma x-ray rechargeable detector, are more expensive. These are often used in specialized situations, like hospital rooms. 

Source: Mart Production on Pexels

Choosing the Right Detector for Your Needs

When choosing a device to measure dose and exposure, it's important to select the equipment that corresponds to your personal requirements. Here are a few key factors to consider:

Applications of Radiation Detection

Personal Protection and Environmental Monitoring

Radiation monitoring is vital for individuals working in high-risk environments, such as nuclear power plants, disaster sites, and medical facilities. These professionals regularly interact with field radiation, and must be conscious of the amount of radiation they encounter in the moment and cumulatively over time. There's a wide selection of radiation detection devices available for such puproses.

Real-Time Radiation Monitoring

Portable detectors allow career professionals to monitor the presence of radiation, and their own exposure to it, with an incredibly fast response time. Handheld Geiger detectors are perfect for contractors, environmental scientists, and other field evaluators to measure things like radon gas levels in homes, radium in antiques, nuclear contaminants at power plants and disaster sites, and naturally occurring radioactive materials in the environment. These are usually quite rugged, and some are even water resistant and come with a digital LCD. They usually form part of a responder radiation kit for emergencies.

Cumulative Exposure Measurement

Professionals that are regularly exposed to radiation through their work must be conscious not just of the amount of radiation present at any given moment, but also the cumulative amount of radiation to which they have been exposed over time. Personal radiation dosimetry devices are designed to be worn consistently and track the total amount of radiation exposure over a period of time. Medical technicians and scientific researchers use personal dosimeters to manage levels of radiation and to triage if necessary.

Scientific Research and Medical Applications

Radiation equipment is commonly found in lab settings, where it is used in scientific research and medical imaging. Scientists use radiation detectors to measure and study radioactive materials and carbon date fossils and other archaeological findings. Medical experts use imaging technologies like radiography and PET scans to make diagnoses and treatment plans.

Professionals in these contexts use less portable, more advanced equipment like scintillation detectors and cloud or ionization chambers to get highly precise readings. 

Beyond Radiation: Understanding EMF Meters

Differentiating Between Radiation and EMF

Electromagnetic fields (EMF) are non-ionizing radiation emitted from electrical devices through the principles of magnetism and electromagnetism. Unlike ionizing radiation, EMF radiation does not have enough energy to remove tightly bound electrons from atoms, and therefore do not cause radioactive decay.

Ionizing radiation comes from alpha, beta, gamma, and x-rays. These radiation particles are capable of ionizing atoms and pose significant (and in some cases, disastrous) health and safety risks.

Electromagnetic fields come from things like radio waves, microwaves, and visible light and can be detected using a conventional LCD EMF detector. While they can be harmful in some contexts, they are considered safe at typical levels of exposure.

When is an EMF Meter Useful?

Electromagnetic field detectors can be used to investigate electrical hazards, ensure that appliances comply with safety standards, and identify sources of aberrantly high EMF exposure. Electromagnetic radiation detectors do not detect ionizing radiation.

Selecting the Right Radiation Detector: A Buyer's Guide

Reputable Brands and Features to Consider

When purchasing a radiation detector, it's important to buy from an authorized seller whose equipment is well-made and reliable. Here are a few popular and reputable equipment manufacturers:

• MIRA Safety: With a focus on personal protection and safety, MIRA Safety specializes in rugged and durable equipment that balances affordability with quality and is favored by emergency response professionals, military personnel, and safety-conscious individuals and families.
  
  
• Thermo Fisher Scientific: Specializing in both industrial and personal radiation detection equipment, Thermo Fisher Scientific manufactures advanced equipment typically used by medical and industrial professionals.
  
  
• Grainger Industrial Supply: Known for offering equipment for industrial and occupational safety, Grainger Industrial Supply offers a range of devices like survey meters that are suitable for various professional environments.
  
  
• SOEKS USA: Popular for their user-friendly interfaces, SOEKs USA focuses on personal radiation detectors designed for every day consumer use.
  
  
• LANDAUER: Renowned for their precise dosimetry services, LANDAUER offers highly accurate radiation monitoring equipment for medical and industrial workers as well as corresponding data processing services.
  
  

Conclusion: Radiation Safety and Informed Choices

Radiation detection and safety are crucial for personal protection, environmental monitoring, and scientific research. Selecting a reliable radiation detector ensures accuracy and safety, preventing exposure and maintaining long-term health. 

Whether you're a medical professional, a researcher, a homeowner, or just a concerned citizen, choosing the right detector tailored to your specific needs is essential. Consult with health professionals or radiation safety experts for specific guidance on your own radiation needs.

Reputable organizations such as the Environmental Protection Agency (EPA) and the National Council on Radiation Protection and Measurements (NCRP) offer valuable resources for further learning about radiation safety. 

By staying informed and utilizing the right tools and expert advice, you can effectively manage radiation risks and ensure a safe environment. Share this article to spread awareness about radiation safety and feel free to ask questions or share your thoughts in the comments section below.